Time delay timer



Feb. 11, 1969 F. J. PAPA, JR

TIME DELAY TIMER Filed Dec.

Sheet of 2 IINVENTOR FRANK PAPA JR. hMH :U

ATTORNEY Feb. 11, 1969 r F. .1. PAPA, JR ,4 I TIME DELAY TIMER Filed Dec. 7. 1966 Sheet. 2 of 2 A INVENTOR FRANK J. PAPA JR.

0 BY 0 11 mm MAI 19.8 N E United States Patent 3,427,412 TIME DELAY TIMER Frank J. Papa, Jr., Montville, N.J., assignor to Industrial Timer Corporation, Parsippany, N.J., a corporation of Delaware Filed Dec. 7, 1966, Ser. No. 599,830

US. Cl. 200-38 Int. Cl. H01h 7/08, 43/10 This invention relates in general to a timer, and more particularly to a time delay timer for timing use in electrical circuitry, and still more particularly'to an improved time delay timer that may be inexpensively manufactured and assembled and which is capable of long life.

The timer of the present invention is adaptable to be made and assembled inexpensively and quickly by primarily using recently developed plastics and sintered metals enabling the timer to be used in conditions where highly corrosive atmosphere is present to thereby improve the life of such a timer. The timer includes a timer motor driving a cam which is essentially oriented for a predetermined time delay, and which will operate a switch actuator following a predeterminetd period of time upon energization of the timer motor. Upon de-energization of the motor, the cam returns to home position so that another switch cycle can be initiated. By use of molded plastics, the casing of the timer and the cam are capable of handling several functions to thereby eliminate the need for a great number of parts. A friction clutch is provided between the timer motor and the cam to protect the motor on reset and during stall.

It is therefore an object of the present invention to provide an improved time delay timer for use in electrical circuitry timing that employs as construction materials the newly developed plastics and sintered metals.

A further object of this invention is in the provision of a time delay timer constructed of molded plastics that enable some parts to carry movable functions thereby eliminating many parts and simplify the overall structure.

Still another object of the invention is to provide a time delay timer that is adjustable to handle a plurality of time delay periods, and which includes a timer motor and means for protecting the timer motor in the form of a friction clutch.

Other objects, features and advantages of the invention will be apparent from the following detailed disclosure, taken in conjunction with the accompanying sheets of drawings, wherein like reference numerals refer to like parts, in which:

FIG. 1 is a front elevational view of the timer according to the present invention;

FIG. 2 is a rear elevational view of the timer;

FIG .3 is a side elevational view of the timer, the opposite side being substantially the same;

FIG. 4 is an enlarged sectional view taken along the horizontal of the timer and illustrating the switch actuating lever;

FIG. 5 is a view of the timer with the rear cover sections removed and with other parts removed for purposes of clarity;

FIG. 6 is an elevational view of the upper section of the back cover as viewed from the inside;

FIG. 7 is an elevational view of the lower section of the back cover as viewed from the inside;

FIG. 8 is a top plan view of the cam, with some parts removed for purposes of clarity;

FIG. 9 is a front elevational view of the cam and timer motor of the timer;

FIG. 10 is an enlarged sectional view taken through the mounting for the main shaft of the time selector;

FIG. 11 is an enlarged sectional view taken through the cam and illustrating the friction clutch;

8 Claims Patented Feb. 11, 1969 ice FIG. 12 is an enlarged fragmentary view of the timer with parts removed and illustrating the coaction between the cam and switch lever looking from the rear; and

FIG. 13 is an enlarged detail sectional view illustrating the coaction between the front cover and the upper section of the back cover.

Referring now to the drawings, the timer of the present invention includes generally a casing 15 having a timer motor 16 mounted on the back side, a time period selector knob 17 mounted on the front side, a cam 18 driven by the timer motor, a switch actuator lever 19 operated by the cam, a switch 20 actuated by the lever 19 and a seletctor stop cam 21 operated by the knob 17 and coacting with the cam 18.

The casing 15 includes a front cover 22, a back cover upper section 23 and a back cover lower section 24. The front cover 22 comprises a front wall or panel 25 having dial indicia 26 on its outer face coacting with the pointer 17a of the selector knob 17, opposed side walls 27, 27 extending normal to the front wall 25, and a sectional top wall 28 that extends between the side walls 27 and rearwardly a short distance from the front wall 25. Oppositely extending cars 29 and 30 projetct from the rear edge of the opposed side walls 27 and have suitable holes therein for connection to mounting brackets 31, 31 that may in turn be mounted on a suitable panel or the like so that the timer may be supported in a desirable place. The lower part of the front cover is open but closed by the mounting of the switch 20 in place between the front wall of the front cover and the back cover lower section 24. The switch 20 is essentially rectangular in shape and is provided with holes extending therethrough for mounting same on locator pins 32 formed integral with and extending from the rear face of the front cover panel 25. Spring clips 32a lock over the ends of the pins 32 to anchor the switch and sockets or holes 33 formed in the back cover lower section 24 receive the outer ends of the pins theretby properly locating the section 24. To further assist in mounting of the switch 20 during assembly of the timer, ridges 34 extend inwardly from the opposed side walls 27 and between which the opposite ends of the switch are received. The switch 20 further includes a plunger 35, and common, normally open and normally closed terminals 36, 37 and 38.

While the lower back cover section 24 is located on the front cover 22 by the switch locating pins 32 and the sockets 33, in order to further assure proper location of the section 24, the opposite edges of the section are notched at 39 to mate with notches 40 formed in the rear edges of the front cover side walls 27, and holes 41 formed in the section 24 fit over bosses 42 supported on projections 43 formed integral with the front cover and extending inwardly from the opposed side walls 27. Thus, the back cover lower section 24 is accurately positioned during assembly of the casing sections. Further, holes 44 are provided in the projections 43 at the center of the bosses 42 for receiving self-tapping screws 45 which extend through holes in mounting ears of the timer motor 16 and secure the timer motor in position on the casinlg as well as secure the lower back cover section 24 in position on the front cover.

The upper section 23 of the back cover closes the upper end of the casing and includes a rear wall 46 that is adapted to be an extension of the back cover lower section 24, and an upper wall section 47 that coacts with the top wall 28 of the front cover to close the upper end of the casing. As seen in FIG. 13, the wall section 47 is received in a notch 48 formed along the edge of the top wall 28. A slot 49 is formed in the wall 46 to accommodate the shaft of the timer motor 16. Further, the lowermost edge portion of the wall section 46 is received under the timer motor and held in place by locking ribs that lock over a lip 51 formed on the free edge of the top wall 28.

The timer motor 16 includes the usual synchronous motor and reduction gear arrangement to produce a desired revolutions per minute of the output shaft designated by the numeral 52, FIG. 11. The drive mechanism in the timer motor released the shaft for free rotation when the motor is not energized, The timing cycles of the timer may be adjusted or changed by interchanging the timer motor.

As seen most clearly in FIG. 11, the cam 18 is mounted on the output shaft 52 through a friction clutch that includes a clutch element 53 suitably secured on the output shaft 52 such as by a setscrew 54. The clutch element includes a friction disc 55 extending radially and a cylindrical portion 56 adapted to freely receive thereon for relative rotation the cam 18. A counterbore 5-7 is provided in the cam into which the cylindrical portion 56 extends. A clutch face 58 is formed on the friction disc 55 and is in engagement with a fiber washer 59 to coact with a clutch face 60 formed on the cam 18. The clutch eleunent 53' is a zinc casting. The cam 18 is molded from a suitable plastic, such as Polysulfone. Further, the casing may be made of a similar plastic. In order to maintain the clutch element and cam in assembled relation and to establish a friction force between same, a friction retainer 61 is suitably secured to the clutch 18 by rivets 62 or the like. The friction retainer is generally ring-shaped and provided with a pair of spring arms 63 that extend inwardly and over steel and Mylar washers 55a and thence over the friction disc 55 of the clutch element 53 to urge the clutch element against the cam 18. It can be appreciated that the friction clutch between the motor and cam protects the motor on reset and during stall.

A cam lobe 64 is integral with the periphery of the cam, and is adapted to engage a roller 65 pivotally mounted on a shaft 66 carried by the switch actuating arm 19. The cam 18 rotates clockwise as shown by the arrows 67 in FIG. 12 and counter-clockwise as shown by the arrow 68 in FIG. 9. The view of the cam in FIG. 9 is the opposite of the view in FIG, 12. The switch actuating arm 19 is also made of a suitable plastic, but the shaft 66 is preferably made of stainless steel and the roller 65 is of a suitable sintered metal. Preferably the roller is of sintered brass and this use of dissimilar materials between the roller and shaft results in long life with minimum wear. The actuator arm 19 is pivoted at one end which is opposite from the end mounting the roller 65, and includes at the pivot end opposed sockets or bearing holes 69 adapted to receive pins 70 and 71 formed in the back cover lower section 24 and the front cover 22, respectively. The pins 70 and 71 are in alignment, which alignment is affected by the orientation of the lower back cover section 24 relative to the front cover 22. Further, the pins 70 and 71 extend from bosses 72 and 73, respectively, all of which are formed integral with the rear cover section and front cover. Thus, the switch actuating arm 19 is pivotally mounted on the pins 70 and 71. The sockets or hearing holes 69 are formed in an enlarged portion 74 of the actuating arm which essentially is further guided and supported by the surfaces of the bosses 72 and 73. To further guide the movement of the switch actuating arm 19, a slide pad 75 is formed integral with the front cover along the inner surface of the front wall .25 thereof and upon which the arm may slide. As the cam lobe 64 strikes the roller 65 and continues in the direction of motor drive, the switch actuating arm 19 is forced away from the cam .18 and in a clockwise direction as viewed in FIG. 12 whereby a setscrew 76, aligned with the switch plunger 35, causes depressing of the plunger and actuation of the switch 20. The setscrew enables the switch to operate at a specific point resulting in longer switch life, by eliminating switch travel beyond the actual point of actuation.

In order to adjust the timer for a particular time period cycle, a selector stop cam 77 having a stop arm 78 thereon is positioned relative to a stop 79 extending from the came 18. The selector stop cam 77 is locked onto a bushing 80 that extends through the front wall 25 of the front cover and also includes thereon washers 8-1 and a friction washer 82 that effectively locks the selector stop cam 77 to the bushing. A main shaft 83 is received within the bushing 80 and locked thereto, and receives the selector knob 17 thereon. Thus, rotation of the selector knob effects rotational setting of the selector stop cam 77 to define the home position against which the stop 79 on the cam 18 will abut. The stop 79 also prevents unlimited rotation of the cam in a clock-wise direction, FIG. 12, in coaction with a stop lug 84 extending from the inner face of the front wall 25 of the front cover 22.

In order to bring the cam 18 back to home position, a coil spring 85 is mounted on the cam to urge the cam continually in a counter-clockwise direction as seen in FIG. 12. The outer end of the spring 85 includes a loop 86 that is received over the stop arm 78, while the inner end is received in an axial slot 87 formed in the cylindrical portion 88 projecting out from the cam, FIG. 11, about which the spring is wound. The front face of the cam serves to contain the spring on one side, while a flange 89 serves to contain the spring on the other side and coact with the cam and cylindrical portion to define a spool for the spring. The flange 89 is held in position against the cam by means of a pin portion 90 that is fractionally held within a bore 91 formed in the cam 18. A stub shaft 92 extends from the flange 89 and is adapted to be received in a hole 93 formed in the inner end of the main shaft 83.

In operation, assuming the switch 20 is suitably connected into electrical circuitry and the timer motor 16 is also connected to a source of energy that may be switched on and off, the timing desired for the electrical circuitry is first selected by rotation of the selector knob 17 to the desired position. Rotation of the selector knob rotates the selector stop cam 77 to bring the stop 78 to a desired position and at the same time move the cam 18 therewith as the spring 85 always urges the cam 18 to home position where the stop 79 on the cam abuts against the stop 78 on the selector stop cam. Upon energization of the timer motor 16, the cam 18 starts to move in a clockwise direction as seen in FIG. 12 where the stop 79 moves away from the stop 78, and when the cam lobe 64 strikes the roller 69 and urges the switch actuating lever 19 to a position to depress the switch plunger 35, the switch 20 is actuated'Preferably, such actuation will de-energize the motor 16 and allow the cam 18 to return to its home position. Thereafter the time cycle may be repeated.

The casing, the cam, the switch actuating arm, the spring retainer 89 and the knob 17 are molded of plastic. Other parts are metal as already described. In view of the foregoing, it can be appreciated that the timer of the present invention may be inexpensively manufactured, but will provide long life and accurate service.

It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention.

The invention is hereby claimed as follows:

1. A time delay timer comprising a casing, a switch within the casing, an actuating lever within the casing for actuating said switch, means for pivotally mounting said lever at one end and a cam roller at the other end, a timer motor having an output shaft, a cam within said casing rotatably driven in one direction by said output shaft and having a lobe engageable with said roller to drive the lever and actuate the switch, a friction clutch between said cam and output shaft, a selector coacting with means on the cam to adjust the time delay and define the home position of the cam, and a spring for driving the cam to home position following de-energization of the motor.

2. A time delay timer as defined in claim 1, wherein said clutch includes a clutch element secured to said output shaft and having a clutch face, a clutch face formed integrally with said cam, a washer between said faces, and a retaining member secured to said cam urging said clutch element and cam toward each other against said washer to create frictional engagement between said cam and clutch element.

3. A time delay timer as defined in claim 1, wherein said casing includes a front cover having a front wall, opposed side walls extending normal to said front wall and a partial top wall extending normal to the front wall and across said side walls and terminating short of the rear edges of the side walls, an upper back cover section having means coacting with said partial top wall to lock in assembly with the front cover and extend between said opposed side walls and partially downwardly therealong, and a lower back cover section extending between said side walls and downwardly to close the remaining portion of the front cover.

4. A time delay timer as defined in claim 3, wherein said means for pivotally mounting said lever includes a pin integral with the front cover, a pin integral with said lower back cover section, and bearing openings on said lever adapted to receive said pins.

5. A time delay timer as defined in claim 4, wherein said front cover and lower back cover section have means coacting to accurately orient the lower back cover section so that said pins are aligned.

6. A time delay timer as defined in claim 5, wherein said casing, said cam, and said lever are molded plastic.

7. A time delay timer as defined in claim 6, wherein said roller is of sintered bronze and is rotatable on a stainless steel shaft mounted on said lever.

8. A time delay timer as defined in claim 1, wherein adjustment means is provided on said lever to operate the switch at a specific point.

References Cited UNITED STATES PATENTS 2,885,001 5/1959 Brown ZOO-35 2,988,608 6/1961 Everard 200-35 3,120,586 2/1964 Van Doren et al 200-35 3,225,151 12/1965 Lagasse 20038 ROBERT K. SCHAEFER, Primary Examiner.

H. O. JONES, Assistant Examiner. 

1. A TIME DELAY TIMER COMPRISING A CASING, A SWITCH WITHIN THE CASING, AN ACTUATING LEVER WITHIN THE CASING FOR ACTUATING SAID SWITCH, MEANS FOR PRIVOTALLY MOUNTING SAID LEVER AT ONE END AND A CAM ROLLER AT THE OTHER END, A TIMER MOTOR HAVING AN OUTPUT SHAFT, A CAM WITHIN SAID CASING ROTATABLY DRIVEN IN ONE DIRECTION BY SAID OUTPUT SHAFT AND HAVING A LOBE ENGAGEABLE WITH SAID ROLLER TO DRIVE THE LEVER AND ACTUATE THE SWITCH, A FRICTION CLUTCH BETWEEN SAID CAM AND OUTPUT SHAFT, A SELECTOR COACTING WITH MEANS ON THE CAM TO ADJUST THE TIME DELAY AND DEFINE THE HOME POSITION OF THE CAM, AND A SPRING FOR DRIVING THE CAM TO HOME POSITION FOLLOWING DE-ENERGIZATION OF THE MOTOR. 